|Publication number||US5049988 A|
|Application number||US 07/392,425|
|Publication date||Sep 17, 1991|
|Filing date||Aug 10, 1989|
|Priority date||Feb 12, 1988|
|Publication number||07392425, 392425, US 5049988 A, US 5049988A, US-A-5049988, US5049988 A, US5049988A|
|Inventors||Alan K. Sefton, David J. Cotton|
|Original Assignee||Pearpoint Limited|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (40), Classifications (12), Legal Events (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to cameras, and particularly to scanning T.V. cameras which are required to produce a tilt-pan effect.
Scanning T.V. cameras are intended for use in inspection, particularly in the inspection of relatively inaccessible areas such as the interiors of sewers and other pipe-lines, and also in other applications such as surveillance; one example of a scanning T.V. camera is the subject of our published British Patent Application, No. 2210530 A, the contents of which are incorporated herein by reference.
Cameras for these purposes should have a wide field of view, usually incorporate a wide-angle lens, and are provided with operating mechanisms to effect scanning of the area to be inspected; surveillance cameras often incorporate a telescopic lens. T.V. cameras usually now incorporate a CCD (charged coupled device) image sensor in the focal plane of the lens, and the sensor can be shifted on the X and Y axes to produce the tilt/pan effects for scanning. Alternatively, the camera may comprise a Vidicon tube which carries an end target sensor and which can be pivoted or otherwise moved to swing the target across the focal plane area of the lens. Suitably, the CCD sensor or Vidicon tube is driven by first and second electric motors that drive to X-Y positions which are detected by relative and absolute feed-back sensors.
It is an object of the present invention to provide a scanning T.V. camera having provision for indicating the section of the field of view which is being inspected.
According to the present invention, there is provided a scanning T.V. camera having an image-sensor which is movable in the plane of the camera lens by drive means, characterised in that means are provided to derive feed-back signals from the image-sensor drive(s) and/or from the image-sensor movements to indicate the position of the image-sensor and thus that section of the field of view which is being inspected.
Suitably, said drive means comprise first and second electric drive motors, and the feed-back signals may be derived from the electric-motor drives by relative and absolute feed-back sensors, the signals being processed to produce an image on a T.V. monitor. The image may comprise a rectangle representing said section and moving within a circular overlay representing said field of view, and a second rectangle may be included to represent a commanded position.
FIG. 1 is a detail sectional elevation showing the operating mechanism for effecting X-Y shift of the sensor of a T.V. camera;
FIG. 2 is a leading end elevation in the direction of arrow II of FIG. 1;
FIGS. 3, 4 and 5 are data-flow diagrams illustrating the micro-processor control system for the operating mechanism; and,
FIG. 6 is a diagrammatic view of a T.V. monitor for use with the T.V. camera of the invention.
The objects and functions of the present camera are similar to those of the camera described in our British Patent Publication No. 2210530 A.
Referring now to FIGS. 1 and 2 of the present drawings the camera has a generally cylindrical chassis member 10 which is mounted within a tubular body (not shown) which carries at its leading end a lens assembly such as a fish-eye lens for wide-angle (inspection) viewing or a telescopic lens assembly for distant (surveillance) viewing. Reference 11 denotes a CCD image sensor which is mounted at the centre of a circular printed circuit board 12 which contains signal de-coupling and which lies in the focal plane of the lens.
The printed circuit board 12 is secured to an annular holder 13 which is mounted, through roller bearings 14, in a rotary cam member 15 which will be referred to as the R-cam. The rearwardly-extending tubular part 16 of the R-cam is carried, through roller bearings 17, in a rotary cam member 18 which will be referred to as the θ-cam. A tube 19 is provided to carry and protect electrical leads (not shown) which extend from a socket (not shown) at the rear end of the tubular body of the camera. This tube is mounted at its ends on corrugated diaphragms 20, 21 which are secured respectively to a ring 22 mounted coaxially in the camera chassis and to the holder 13. The diaphragms are flexible but torsionally rigid to maintain the correct (upright) orientation of the image sensor 11.
In use of the camera, X-Y movement of the sensor 11 in the focal plane of the lens is effected by the action of electric motors 23 (the θ-motor) and 24 (the R-motor). The θ-motor rotates the θ-cam 18 through a drive pinion 25, and the R-motor rotates the R-cam 15 through a drive pinion 26 and a planet-drive sleeve 27 which is rotatably mounted in the camera chassis and which engages planet pinion part 28 of the R-cam. Thus, the θ-cam controls the position of the centre CR of the R-cam and rotation of the R-cam moves the centre CS of the sensor 11 relative to centre CR. The reference CC denotes the image centre of the camera, and it will be appreciated that appropriate rotation of the two cams under the action of the motors 23 and 24 will shift the sensor centre CS a desired vector distance from the image centre CC.
The interaction between the R-cam and the θ-cam caused by the planetary gearing is eliminated from the control system by means of a known constant installed in the control software to cancel the interaction. Further computation is used to remove the change of θ with operation of the R-cam.
θ-cam (angular) position feedback is achieved by an opto position sensor 29 and an absolute position sensor 30, which coact with an optical encoder disc 31 on the θ-cam. R-cam position feedback is derived from incremental sensing of the planet drive sleeve 27 by opto sensor 31 which coacts with encoder disc 33, and absolute sensing by a sensor 34 reading an encoder band 34A around the R-cam 15.
The operation of the drive mechanism for the CCD sensor 11 is controlled by a micro-processor system, as illustrated in FIGS. 3 and 4 of the present drawings and outlined as follows.
Quadrature signals from the incremental sensors 29 and 32 reading encoder discs 31 and 33, respectively, are used to increment and decrement the R and θ counters, position information from the absolute sensors 30 and 34 having been used to initialise the counters when the camera is switched on.
The micro-processor is programmed as shown in the dataflow diagram of FIG. 3 and the circuit diagram of FIG. 6.
The commanded X-Y position is converted to R-θ co-ordinates, and these values are used to compute desired encoder values. A decision is made as to the fastest route to this position, and the servo routine drives the motors until the required position is reached.
To provide remote display of position, the micro-processor computes the R-θ co-ordinates from the encoder counter values, translates these to X-Y and transmits these values to the control link. Optionally, the position may be drawn on to the camera video signal for automatic display on a monitor, as indicated in FIGS. 5 and 6.
FIG. 6 shows a T.V. monitor with an optical overlay 35 on the screen 36 which displays the images from the camera. The overlay is formed as a circle 37 representing the full area of coverage of the camera lens, and two small rectangles 36 which represent the relative position and size of the area section being viewed by the camera. Overall control of the camera may be by a remote-sited controller comprising a position in-putting device such as joystick, rolling ball, touch pac or rate joystick, connected to a micro-processor with attached graphics display unit locked to the camera video. The micro-processor sends data to the camera giving the desired position or motion. The camera sends data to the micro-processor giving current position. The micro-processor displays, via the graphics display, the two positions, i.e. current position and desired position, unless a rate control system is used when only current position is displayed.
In use, the joystick is operated to move the smaller (inner) rectangle 38 to the desired or commanded position; the larger rectangle which is derived from the encoder sensors and reflects the position of the CCD sensor 11, will quickly follow and surround the smaller rectangle to confirm that the CCD sensor has reached the desired viewing position.
Only one embodiment has been selected to illustrate the invention, but it will be appreciated by those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as defined in the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4238828 *||Oct 6, 1978||Dec 9, 1980||The Secretary Of State For Industry In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland||Position detecting apparatus|
|US4258388 *||Feb 2, 1979||Mar 24, 1981||The United States Of America As Represented By The Secretary Of The Army||Optical indexing system|
|US4321625 *||Jun 13, 1980||Mar 23, 1982||Lectrolarm Custom Systems, Inc.||Control system for plurality of video cameras|
|US4369467 *||Jan 19, 1981||Jan 18, 1983||Lectrolarm Custom Systems, Inc.||Video camera monitoring system|
|US4740839 *||Jun 12, 1987||Apr 26, 1988||Phillips William R||TV surveillance system that requires no mechanical motion|
|US4881122 *||Nov 29, 1988||Nov 14, 1989||Kanji Murakami||Three-dimensional shooting video camera apparatus|
|GB2210530A *||Title not available|
|GB2215941A *||Title not available|
|GB2215942A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5422653 *||Jan 7, 1993||Jun 6, 1995||Maguire, Jr.; Francis J.||Passive virtual reality|
|US5633681 *||Mar 6, 1995||May 27, 1997||Picturetel Corporation||Electrically controlled camera positioning system|
|US5644324 *||Mar 3, 1993||Jul 1, 1997||Maguire, Jr.; Francis J.||Apparatus and method for presenting successive images|
|US5719622 *||Feb 23, 1996||Feb 17, 1998||The Regents Of The University Of Michigan||Visual control selection of remote mechanisms|
|US5734421 *||May 30, 1995||Mar 31, 1998||Maguire, Jr.; Francis J.||Apparatus for inducing attitudinal head movements for passive virtual reality|
|US5742329 *||Jul 14, 1997||Apr 21, 1998||Canon Kabushiki Kaisha||Image pickup system and communication system for use in video conference system or the like|
|US5777668 *||Jul 26, 1996||Jul 7, 1998||Amano & Associates Incorporated||Furnace monitoring camera with pivoting zoom lens|
|US5836869 *||Nov 1, 1995||Nov 17, 1998||Olympus Optical Co., Ltd.||Image tracking endoscope system|
|US5999214 *||Jan 22, 1998||Dec 7, 1999||Canon Kabushiki Kaisha||Image pickup system and communication system for use in video conference or the like|
|US6036637 *||Apr 22, 1998||Mar 14, 2000||Olympus Optical Co., Ltd.||Treating system utilizing an endoscope|
|US6094182 *||Jun 30, 1997||Jul 25, 2000||Maguire, Jr.; Francis J.||Apparatus and method for providing images for viewing at various distances|
|US6181371||Feb 3, 1997||Jan 30, 2001||Francis J Maguire, Jr.||Apparatus for inducing attitudinal head movements for passive virtual reality|
|US6307589||May 4, 1998||Oct 23, 2001||Francis J. Maquire, Jr.||Head mounted camera with eye monitor and stereo embodiments thereof|
|US6693666||Dec 11, 1997||Feb 17, 2004||Interval Research Corporation||Moving imager camera for track and range capture|
|US6760063 *||Apr 2, 1997||Jul 6, 2004||Canon Kabushiki Kaisha||Camera control apparatus and method|
|US6798443||Jan 29, 2001||Sep 28, 2004||Francis J. Maguire, Jr.||Apparatus for inducing attitudinal head movements for passive virtual reality|
|US6967678||Jan 12, 2001||Nov 22, 2005||Vulcan Patents Llc||Moving imager camera for track and range capture|
|US7439940||Oct 22, 2001||Oct 21, 2008||Maguire Jr Francis J||Passive virtual reality|
|US7486311||Dec 18, 2003||Feb 3, 2009||Vulcan Patents Llc||Moving imager camera for track and range capture|
|US7567702||Jul 21, 2005||Jul 28, 2009||Vulcan Patents Llc||Data processing system and method|
|US7724278||Sep 22, 2004||May 25, 2010||Maguire Francis J Jr||Apparatus with moveable headrest for viewing images from a changing direction-of-view|
|US7847826||Aug 14, 2008||Dec 7, 2010||Interval Licensing Llc||Moving imager camera for track and range capture|
|US7925077||Jan 30, 2009||Apr 12, 2011||Tyzx, Inc.||Generation of a disparity result with low latency|
|US8493461||Nov 16, 2010||Jul 23, 2013||Interval Licensing Llc||Moving imager camera for track and range capture|
|US8717450||Sep 14, 2012||May 6, 2014||Interval Licensing Llc||Moving imager camera for track and range capture|
|US8860780 *||Sep 27, 2005||Oct 14, 2014||Grandeye, Ltd.||Automatic pivoting in a wide-angle video camera|
|US9183461||May 9, 2013||Nov 10, 2015||Intel Corporation||Systems and methods for row causal scan-order optimization stereo matching|
|US20040135886 *||Dec 18, 2003||Jul 15, 2004||Baker Henry H||Moving imager camera for track and range capture|
|US20050041100 *||Sep 22, 2004||Feb 24, 2005||Maguire Francis J.||Apparatus for inducing attitudinal head movements for passive virtual reality|
|US20060013473 *||Jul 21, 2005||Jan 19, 2006||Vulcan Patents Llc||Data processing system and method|
|US20080303908 *||Aug 14, 2008||Dec 11, 2008||Baker Henry H||Moving imager camera for track and range capture|
|US20090136091 *||Jan 30, 2009||May 28, 2009||John Iselin Woodfill||Data processing system and method|
|US20110058033 *||Nov 16, 2010||Mar 10, 2011||Baker Henry H||Moving imager camera for track and range capture|
|USRE44925||Apr 11, 2011||Jun 3, 2014||Transcenic, Inc.||Spatial referenced photographic system with navigation arrangement|
|USRE45062||Feb 26, 2013||Aug 5, 2014||Susan C. Maguire||Apparatus for inducing attitudinal head movements for passive virtual reality|
|USRE45114||Mar 15, 2013||Sep 9, 2014||Susan C. Maguire||Apparatus with moveable headrest for viewing images from a changing direction-of-view|
|EP0565830A2 *||Feb 20, 1993||Oct 20, 1993||International Business Machines Corporation||Method and apparatus for user control by deriving next states of a process from a current state and by providing a visual presentation of the derived next states|
|WO1995011566A1 *||Sep 28, 1994||Apr 27, 1995||Videoconferencing Systems, Inc.||Adaptive videoconferencing system|
|WO1996024216A1 *||Jan 31, 1996||Aug 8, 1996||Transcenic, Inc.||Spatial referenced photography|
|WO1996027979A1 *||Mar 6, 1996||Sep 12, 1996||Picturetel Corporation||Camera positioning system|
|U.S. Classification||348/143, 348/374, 348/E05.027, 348/219.1, 348/E05.042, 348/369|
|International Classification||H04N5/225, H04N5/232|
|Cooperative Classification||H04N5/2253, H04N5/232|
|European Classification||H04N5/225C3, H04N5/232|
|Aug 10, 1989||AS||Assignment|
Owner name: PEARPOINT LIMITED, UNITED KINGDOM
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:SEFTON, ALAN K.;COTTON, DAVID J.;REEL/FRAME:005114/0187
Effective date: 19890724
|Mar 16, 1995||FPAY||Fee payment|
Year of fee payment: 4
|Mar 17, 1999||FPAY||Fee payment|
Year of fee payment: 8
|Mar 26, 2003||SULP||Surcharge for late payment|
Year of fee payment: 11
|Mar 26, 2003||FPAY||Fee payment|
Year of fee payment: 12
|Apr 2, 2003||REMI||Maintenance fee reminder mailed|
|Nov 19, 2003||AS||Assignment|
Owner name: RADIODETECTION LIMITED, UNITED KINGDOM
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:PEARPOINT LIMITED;REEL/FRAME:014709/0027
Effective date: 20031023